1. Field of the Invention
This invention relates to steel wires for use in stringed instruments, such as piano wires of pianos, and to manufacturing methods therefor.
This application claims priority on Japanese Patent Application No. 2003-399534, the content of which is incorporated herein by reference.
2. Description of the Related Art
Conventionally, steel wires such as piano wires defined in the Japanese Industrial Standard, that is, JIS G 3522, which are manufactured using piano wire materials (or rolled wire materials) defined in JIS G 3502, are used for so-called music wires or steel wires for use in stringed instruments such as pianos.
According to Japanese Patent Application Publication No. S53-95616, it is necessary to provide music wires (or strings) of stringed instruments with a relatively high tensile strength and a relatively high elasticity, which significantly influences the sound quality of stringed instruments. It is also required that music wires have overall characteristics in which their sectional areas have uniform and true circular shapes, and they are resistant to corrosion.
Even though music wires are developed in consideration of the aforementioned characteristics, the sound quality realized by the conventional music wires is imperfect, and therefore various attempts have been made to further improve music wires in terms of the sound quality of stringed musical instruments.
For example, Japanese Patent Application Publication No. S63-2524 discloses a technology regarding the straightening process using straightening rolls after die drawing. Japanese Patent Application Publication No. H10-105155 discloses the technology regarding the plating on surfaces of steel wires so as to demonstrate anti-corrosion effects. In addition, various documents disclose methods for further improving musical instruments in sound quality by using steel wires while maintaining satisfactory performance substantially equivalent to that of conventional musical instruments. For example, Japanese Patent Application Publication No. S53-95616 discloses that prescribed portions of strings struck by hammers are made different in sectional areas compared with other portions of strings. Japanese Patent Application Publication No. S53-95613 discloses the technology for partially changing the winding density of lines wound about wire cores (or music wires).
As described above, various improvements have been made with respect to music wires. However, due to a strong demand for producing superior sound quality, it is required to produce further improved music wires to cope with demands for further improvements in the sound quality of musical instruments.